Robust Fiducial Marker for Flexible Surfaces

{
  "publication_number": "US2020082200A1",
  "country": "US",
  "kind": "A1",
  "title": "Robust Fiducial Marker for Flexible Surfaces",
  "abstract": "The present invention discloses fiducial marker systems or tag systems and methods to detect and decode a tag. In one aspect, a tag comprises four corners. Two upper corners are interconnected to form a detection area. Two lower corners are interconnected to form another detection area. The detection areas are interconnected by a path. The path divides the space between the detection areas into two coding areas. In another aspect, a tag comprises four corners. The four corners are interconnected by multiple paths. The multiple paths divide the space defined by the four corners into multiple coding areas.",
  "claims": [
    "1. A method for detecting and decoding a square-shaped or rectangular-shaped tag captured in an image, the tag being divided into a plurality of cells based on a grid pattern, each cell in a first full row of cells along a first edge of the tag being dark color, the first full row of cells including a first corner cell and a second corner cell of the tag, the first full row of cells defining a first area of the tag, each cell in a second full row of cells along a second edge of the tag being dark color, the first edge being opposite to the second edge, the second full row of cells including a third corner cell and a fourth corner cell of the tag, the second full row of cells defining a second area of the tag, the first area and the second area being interconnected by a path of connected cells in dark color, each cell in the path of connected cells located not along any edge of the tag, remaining cells of the plurality of cells being either dark color or light color, the method comprising: detecting the first, second, third, and fourth corner cells in the image; determining whether the first and second corner cells are interconnected in the first area in the image; determining whether the third and fourth corner cells are interconnected in the second area in the image; determining whether the first area and the second area are interconnected by the path of connected cells in the image; and decoding the tag based on colors of the remaining cells of the plurality of cells. 2. The method of claim 1, wherein the path of connected cells forms a straight line. 3. The method of claim 1, wherein said decoding is also based on colors of the cells in the path of connected cells. 4. The method of claim 1, wherein the tag is surrounded by a border region in light color. 5. The method of claim 1, wherein a portion of an image of a code is presented using the first or second area, the code including at least one of a plurality of elements, the plurality of elements including a numerical number and a letter. 6. A method comprising: attaching a tag to a target object, wherein the tag is a square-shaped or rectangular-shaped tag, the tag being divided into a plurality of cells based on a grid pattern, each cell in a first full row of border cells being dark color, the first full row of border cells including a first corner cell and a second corner cell of the tag, the first full row of border cells defining a first area of the tag, each cell in a second full row of border cells being dark color, the second full row of border cells including a third corner cell and a fourth corner cell of the tag, the second full row of border cells defining a second area of the tag, the first area and the second area being interconnected by a path of connected interior cells in dark color, remaining cells of the plurality of cells being either dark color or light color; using a camera to capture an image comprising the tag; detecting the first, second, third, and fourth corner cells in the image; determining whether the first and second corner cells are interconnected in the first area in the image; determining whether the third and fourth corner cells are interconnected in the second area in the image; determining whether the first area and the second area are interconnected by the path of connected interior cells in the image; and decoding the tag based on colors of the remaining cells of the plurality of cells. 7. The method of claim 6, wherein the path of connected interior cells forms a straight line. 8. The method of claim 6, wherein said decoding is also based on colors of the cells in the path of connected interior cells. 9. The method of claim 6, wherein the tag is surrounded by a border region in light color. 10. The method of claim 6, wherein a portion of a code's image is presented using the first or second area, the code including at least one of a plurality of elements, the plurality of elements including a numerical number and a letter. 11. A system for using a fiducial marker, comprising: a square-shaped or rectangular-shaped tag, the tag being divided into a plurality of cells based on a grid pattern, each cell in a first full row of cells along a first edge of the tag being dark color, the first full row of cells including a first corner cell and a second corner cell of the tag, the first full row of cells defining a first area of the tag, each cell in a second full row of cells along a second edge of the tag being dark color, the first edge being opposite to the second edge, the second full row of cells including a third corner cell and a fourth corner cell of the tag, the second full row of cells defining a second area of the tag, the first area and the second area being interconnected by a path of connected cells in dark color, each cell in the path of connected cells located not on any edge of the tag, remaining cells of the plurality of cells being either dark color or light color; a camera for capturing an image comprising the tag; and a processing unit that executes instructions to perform the steps comprising: detecting the first, second, third, and fourth corner cells in the image, determining whether the first and second corner cells are interconnected in the first area in the image, determining whether the third and fourth corner cells are interconnected in the second area in the image, determining whether the first area and the second area are interconnected by the path of connected cells in the image, and decoding the tag based on colors of the remaining cells of the plurality of cells. 12. The system of claim 11, wherein the path of connected cells forms a straight line. 13. The system of claim 11, wherein the path of connected cells contains coded information. 14. The system of claim 11, wherein the tag is surrounded by a border region in light color. 15. The system of claim 11, wherein a portion of a code's image is presented using the first or second area, the code including at least one of a plurality of elements, the plurality of elements including a numerical number and a letter. 16. A tag as a fiducial marker, comprising: a plurality of cells arranged in a grid pattern, the plurality of cells forming a square or rectangular shape, each cell in a first full row of cells along a first edge of the tag being dark color, the first full row of cells including a first corner cell and a second corner cell of the tag, the first full row of cells defining a first area of the tag, each cell in a second full row of cells along a second edge of the tag being dark color, the first edge being opposite to the second edge, the second full row of cells including a third corner cell and a fourth corner cell of the tag, the second full row of cells defining a second area of the tag, the first area and the second area being interconnected by a path of connected interior cells in dark color, remaining cells of the plurality of cells being either dark color or light color. 17. The tag of claim 16, wherein the path of connected cells forms a straight line. 18. The tag of claim 16, wherein the path of connected cells contains coded information. 19. The tag of claim 16, wherein a portion of an image of a code is presented using the first or second area, the code including at least one of a plurality of elements, the plurality of elements including a numerical number and a letter. 20. A method for detecting and decoding a square-shaped or rectangular-shaped tag captured in an image, the tag being divided into a plurality of cells based on a grid pattern and having a first, second, third, and fourth corner cells being in dark color and interconnected by a plurality of connected cells in dark color, each cell, except the first, second, third, and fourth corner cells and the plurality of connected cells, being either dark color or light color, the method comprising: detecting the first, second, third, and fourth corner cells in the image; determining whether the first, second, third, and fourth corner cells are interconnected by the plurality of connected cells in dark color in the image; and decoding the tag based on colors of the cells except the first, second, third, and fourth corner cells."
  ],
  "cpc": [
    "G06T 7/74",
    "G06K 9/4638",
    "G06K 9/4652",
    "G06T 2207/10024",
    "G06T 2207/30208",
    "G06V 10/245",
    "G06V 10/457",
    "G06V 10/56"
  ],
  "assignees": [
    "DILILI LABS INC"
  ],
  "filing_date": "2019-09-11",
  "publication_date": "2020-03-12",
  "priority_date": "2018-09-11",
  "application_number": "US-201916566892-A",
  "family_id": "69719879"
}